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`J. D. HILLIAVRD ELECTRIC SWITCH Original Filed Feb. a, 1921 Patented Aug. 25, 1925.

UNITED STATES PATENT OFFICE.

JOHN D. HILLIARD, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, OF SCHENECTADY, NEW YORK, A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Original application tiled February 8, 1921, Serial No. 443,440. Divided and this application filed November 23, 1922.

To all whom. it 'may concern.'

Be it known that I, JOHN D. Hummm), a citizen of the United States, residingfat Schenectady, in the county of Schenectady, State of' New York, have invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

My invention relates to electric switches and especially to switches of the typewheref in a circuit is broken by the separation of contacts or electrodes immersed in an insulating or arcextinguishing fluid.

When opening high power circuits under oil, the arc formed upon separation of the switch contacts causes a certain amount of the oil to be disassociated or volatilized,

thereby producing within the body of the oil cient to eject oil from the tanker even to injure the tank itself. The oil :ejected from the tank is in a more or less atonized condition and is often carbonized so; Lthat 'it forms a. blackv deposit on objects with which it comes into contact. ejected by highly heated gas which, upon contact with the air, may causeondary explosions of sufficient violence to urst the oil tank or tear it from its supportsl' :Evt-n;

`where the direct injury from thiI eriplosion is slight, the fire risk is increased and ithas frequently happened that. such explosions have resulted in a short circuitwhitlh scriously interfered with the operation of the system to which the switch was connected. l

According to the invention disclosed in my copending application Serial No; 443,440, filed February 8, 1921, of which this application is a division and which -application is assigned to the same assignee as the present applicaton,'I so construct the sw itch' that when the circuit is broken under-'oil no oil is ejected from the switch tank and secondar`y explosions caused by contact of heated gas with the air are prevented. 'lo accomplish this` result, I interpose in the path of the fluid in motion by the are a means which will prevent the ejection of liquid from the tank, will separate a large part of the oil vapor and atomized oil from the gas, and will cool the fluids ejected from the tank to a temperature below that. at which they spontaneously ignite upon contact with The o1 .is'

Serial No. 602,703.

flow is impeded to cool it. and separate it from theintermingled gases. iVhile the specific means used to break up the moving fluids may assume a variety of forms, I prefer to use a material having a high dielectric strength suchas quartz gravel which may vary considerably in size, pebbles from 1/ to 3A inch being satisfactory in many cases.

My present invention has for its purpose the provision of means by which the perforated barrier described above may be utilized in connection with a fluid break switch of-the well known explosion chamber or oil blast type, and will be better understood from the following description taken in connection with the accompanying drawing, its stlxope` being pointed out in the appended cal s.

Referring ndw to the drawing there is illustrated in the single figure thereof a tank 1-eontaining an insulating liquid 2 witliitiivhich is immersed an 'explosion eham her casing 3 formed of steel or other suitable material and arranged to be supported from thc top (not shown) of'the tank 1 by the stationary contact or electrode 4 and the insulator 5 which is shown as partially broken away. The explosion chamber easing 3 is provided with openings (5 at its upper end within which are adapted to be seated valve heads 7 carried upon stems 8 arranged to slide within the recesses t) formed in the circular plate 10. Springs 11 are interposed between the valve heads 7 and the plate 10 for maintaining the valves in closed position. 'lhe plate 10 and the insulating casing l?, together form a receptacle which surrounds the top and sidesvof the explosion chamber 3 but does ,not cn- \elop the bottom thereof. The plate l0 is provided with screw threads around its periphery which engage threads 12' -formed in a metallic ring 12 mounted in the insulating casing 13. The plate l() foi-ius a tight joint between the easings 3 and 13. Small bleed holes 14 and 23 are provided for the purpose of erinitting the oilto assume its nornial leve within the explosion champel' and the annular chamber formed aronnt by the casing 13.

Bet-menthe casings '3 and 13 is arranged a barrier 15 compose.. of gravel or other suitable material and held in place. by perforated rings lt and l? which are. maintained in fixed position by means of pins 18 and 19. An insulator-2t) issnpported through an opening in tliexbottoin o-f tl`e' explosion'chamber easingand is provided' at its center with an opening*- through v-:hieh

the tubular movable eleetrmletl is arranged switch. 'llie explosion-eliaml'ieifis lined o n *the inside and covered on the outside with a-n insulating material 'l`he insulating 'fluid 2 in and around the. casing 13 is normally maintained at a level above the top of the chamber t'ornied be? etl'eetive in interrupting the.- areby reason of the. fart that itf blows'a-fflilz'lstl ofinsulat'ing liquid direetly across the path of the arc drawn between parts 4 and-21"t`herehy eooling and extinguishingthesamels. A'

The pressure within the explosion e.l\:un-

bei-.is limited by the valves ivliieli open at a. predetei'inined pressure and pei'iiiit the gas and vapor to esea'pe.l into tlre'rliainlier beneath the. plate 1U wliieh may eont. ain above the. lowei edge of the ora-ning 14 an amount ol' air suflieientto form a cushionfor the eseaping gas dien-by damage tn the. apparatus by the force of the explosion is prevented. 'l'lie prei-:sure ereated within this spare causes thevapor and gas to be an out-let; atone end' thereof` a .pressure chamber within said reeeptaele having an outlet at. the Aopposite. end thereof, and a bar-rier composed Vof granular materia-l between said receptacle and said chamber.

2. In a. switch, a. piessuiechamber oontaining a liquid; delectrodes arranged to form an are" withiii said eliamber, Said chainlier having at. the opposite ends thereof a liquid outlet for 'discharging said liquid into the. path. of said are and a gas outlet foi' diseliaiging the gas created by 'said are', and means surioundin'g said cl'ianiber for eooling said gas. A

3. In a. ttuid switch, a tank adapted to Aeontain an insulating fluid, a receptacle' therein having an opening at, one en d'rtliere of, -a seeond reeeptaele. enelosingfsaid first named reeeptaele and having :in opening attlie opposite end thereof', switch eontacts within said first named receptacle, and means'latween said r( re-ptaeles for moling the gases formed upon the separation of said eontaets.

4.. I n al fluid switeli. 'af receptacle having an opening atoiie eiidjthereof. a 'second ieeeptaele enclosing said '.'f rst named 1B- eeptaele and having an opening at. .tlie o posite end thereof, switehletintaets within said fiist named reeeptaele. and 'gravel loeated between said 'reeeptaeles for cooling the and condensing the vapois formed upon the opening of the. eireuit.

:T ln :n.fliiid swteh.- a tank adapted to Contain au insulating fluid, a. reeeptaele within said tank. said ieeeptaele being open at bottom` a seeond i'eeeptarle wit-hin said first named reeeptaele. said .la-.eend receptacle being ada'ptd to he. submerged in and filled wit,h an insnlati'ng fluid` said second receptacle being v,prdrided with :in opening at its top, areing eleetrodes within ,said seeond receptacle. and granular coolingl material between said reeeptaeles.

"(.,ln al. fluid switeh` a tanlt adapted to -eontain an insulating fluid` a receptacle within said tanl said i'eeeptaele being open' at. its bottomy'a second reeeptaele, within said first named reeeptaele, said second reeeptaele. being adapted to be sulnnerged'iri and filled with an insulating'. fluid. said seeond reeeptaele beingr provided with` an opening at its top, a valve -seated in said opening and adapted to openat a predeter-- mined pressure` al stationary electrode located in said second rereptaele. an electrode. adapted to coopera-te. with said stationary electrode and movable through an .opening in the. lower part of said second receptacle and granular eooling material between said reeeptaeles. i i

ln witness wliereot l have hereunto set my hand this 22nd day of November, |922.

JOll N l). lll fililA lll). 

